JP2011105455A - Elevator device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control the speed of a car in an emergency stop without newly providing a motor with a rotation sensor. <P>SOLUTION: A speed estimator 30 estimates the rotational speed with the electric potentials of three phases (U-phase, V-phase and W-phase) of the motor 6 being inputs, and outputs the rotational speed to a brake control device 28. If a car 1 must be subjected to the emergency stop when the car 1 is running, the brake control device 28 controls a brake device 8 based on the speed signal output from the speed estimator 30, and controls the rotation of the motor 6 so that the car 1 is smoothly stopped. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an elevator apparatus capable of controlling a braking force of a brake apparatus that brakes a car.

  In the conventional elevator apparatus, the deceleration of the car is variably controlled by controlling the energization current to the brake coil at the time of emergency stop. At the time of an emergency stop, a speed command based on an emergency stop speed reference pattern having a predetermined deceleration is output from the speed reference generation unit (see, for example, Patent Document 1).

JP-A-7-206288

  In recent years, permanent magnet motors (PM motors) that do not require current for the field have been applied to many elevator apparatuses. In general, a sensor that detects the magnetic pole position of a permanent magnet is used to control the PM motor. On the other hand, a sensorless control system that does not use a sensor has been developed from the viewpoint of structural restrictions and cost reduction in an elevator apparatus. In this sensorless control method, the rotation state of the motor is estimated based on characteristics such as voltage and current applied from the inverter to the motor. However, since power supply to the motor is interrupted during an emergency stop, the rotation speed of the motor cannot be estimated from the voltage or current value applied by the inverter.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an elevator apparatus that can control the speed of a car during an emergency stop without newly providing a rotation sensor in the electric motor. And

  The elevator apparatus according to the present invention includes a car, an electric motor that drives the car, an elevator control device that controls the electric motor, a brake device that brakes the running of the car, a brake control device that controls the brake device, and a rotational speed of the electric motor. The brake control device includes a speed estimator, and controls the braking force generated by the brake device with reference to the speed estimated by the speed estimator during an emergency stop.

  In the elevator apparatus according to the present invention, since the brake control device controls the braking force generated by the brake device with reference to the speed estimated by the speed estimator at the time of emergency stop of the car, a new rotation sensor is added to the electric motor. Without providing it, the speed of the car can be controlled during an emergency stop.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the elevator apparatus by Embodiment 1 of this invention. It is a block diagram which shows the speed estimator of FIG. It is a graph which shows the time change of the voltage between terminals between each phase when the electric motor of FIG. 1 rotates at constant speed. It is a block diagram which shows the structure of the rotational speed calculating means of FIG. It is a graph which shows a mode that the voltage between terminals is fluctuate | varied with the rotational speed of the electric motor of FIG. It is a block diagram which shows the speed estimator of the elevator apparatus by Embodiment 2 of this invention. It is a graph which shows the time change of two sets of voltage between terminals when the electric motor of FIG. 1 rotates at constant speed. FIG. 7 is a graph showing temporal changes in the voltage between two sets of terminals when the rotation directions are opposite. It is a graph which shows the time change of the speed of a cage | basket | car and the time change of the state of a forced brake switch when the stop distance is restrict | limited by the forced deceleration apparatus by Embodiment 3 of this invention. It is a graph which shows the relationship between the car speed and distance at the time of restrict | limiting a stop distance with the forced deceleration apparatus by Embodiment 3, and the relationship between the state of a forced brake switch, and distance.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
1 is a block diagram showing an elevator apparatus according to Embodiment 1 of the present invention. In the figure, a car 1 and a counterweight 2 are suspended in a hoistway by suspension means 3. As the suspension means 3, a plurality of ropes or belts are used.

  A hoisting machine 4 that raises and lowers the car 1 and the counterweight 2 is installed at the upper part of the hoistway. The hoisting machine 4 includes a driving sheave 5 around which the suspension means 3 is wound, an electric motor 6 that generates driving torque and rotates the driving sheave 5, and a brake wheel that rotates integrally with the driving sheave 5 (for example, a brake drum or a brake). Disk) 7 and a brake device 8 that generates braking torque and brakes the rotation of the brake wheel 7.

  In this example, the drive sheave 5 and the brake wheel 7 are fixed to the rotating shaft of the electric motor 6. As the electric motor 6, a PM electric motor is used. Further, an electromagnetic brake device is used as the brake device 8.

  In the electromagnetic brake device, the brake shoe is pressed against the braking surface of the brake wheel 7 by the spring force of the brake spring, the rotation of the brake wheel 7 and the drive sheave 5 is braked, and the car 1 is braked. Further, by exciting the electromagnetic magnet, the brake shoe is pulled away from the braking surface, and the braking force is released.

  A car buffer 9 and a counterweight buffer 10 are installed at the bottom of the hoistway. The car shock absorber 9 is disposed directly under the car 1 and alleviates the impact when the car 1 collides with the bottom of the hoistway. The counterweight shock absorber 10 is disposed directly below the counterweight 2 and alleviates the impact when the counterweight 2 collides with the bottom of the hoistway.

  A speed governor 11 is installed in the upper part of the hoistway. The governor 11 includes a governor sheave 12 and a governor encoder 13 that generates a signal corresponding to the rotation of the governor sheave 12. The governor sheave 12 is wrapped around the upper end of a loop governor rope 14. The lower end portion of the governor rope 14 is wound around a tension wheel 15 disposed at the lower part of the hoistway.

  The governor rope 14 is connected to the car 1. Thereby, when the car 1 is raised and lowered, the governor rope 14 is circulated, and the governor sheave 12 is rotated at a rotational speed corresponding to the traveling speed of the car 1.

  The electric motor 6 is controlled by the elevator control device 21 via the inverter 22. A power supply switch 23 is provided between the inverter 22 and the electric motor 6. Opening and closing of the power supply switch 23 is controlled by the elevator control device 21.

  A brake coil 24 is provided in the electromagnetic magnet of the brake device 8. The brake coil 24 is connected to a brake power supply 25. A control brake switch 26 and a forced brake switch 27 are connected in series between the brake coil 24 and the brake power supply 25.

  On / off of the control brake switch 26 is controlled by a brake control device 28. When the car 1 travels, the brake control device 28 receives a command from the elevator control device 21 and applies a voltage to the brake coil 24 to release the braking force that keeps the rotation of the drive sheave 5 stationary.

  Further, the brake control device 28 controls the braking force applied by the brake device 8 at the time of emergency stop of the car 1 to prevent the deceleration of the car 1 from becoming excessive. At this time, the brake control device 28 applies a predetermined voltage to the brake coil 24 by, for example, turning on and off the control brake switch 26 at a preset switching duty (for example, 50%), thereby increasing the braking force. Control.

  On / off of the forced brake switch 27 is controlled by a forced deceleration device 29. The forced deceleration device 29 obtains the position of the car 1 based on the signal from the governor encoder 13. In addition, the forced deceleration device 29 forcibly operates the brake device 8 by operating the forced brake switch 27 as necessary based on a signal from the governor encoder 13 or a command from the elevator control device 21. When the forced brake switch 27 is turned off, the power supply to the brake coil 24 is cut off, and the maximum braking force of the brake device 8 is applied to the brake wheel 7.

  The speed estimator 30 indirectly estimates the rotational speed of the electric motor 6 based on a signal obtained from an electric wire connected to the electric motor 6 itself. In this example, the speed estimator 30 estimates the rotational speed using the three-phase (U-phase, V-phase, W-phase) potential of the electric motor 6 as an input, and outputs it to the brake control device 28. The brake control device 28 outputs a speed signal output from the speed estimator 30 when the car 1 needs to be emergency stopped, for example, when an emergency stop command is received from the elevator control device 21 while the car 1 is traveling. Based on this, the brake device 8 is controlled to control the rotation of the electric motor 6 so that the car 1 stops gently (so that the deceleration of the car 1 does not become excessive).

  FIG. 2 is a block diagram showing the speed estimator 30 of FIG. The speed estimator 30 includes voltage detection means 31 and rotation speed calculation means 32. The voltage detection means 31 detects an input voltage and outputs a terminal voltage between the phases. The rotation speed calculation means 32 estimates and outputs the rotation speed based on the voltage between the terminals.

  FIG. 3 is a graph showing the time change of the voltage between the terminals between the phases when the electric motor 6 of FIG. 1 rotates at a constant speed. The voltage between the terminals changes positively and negatively for one cycle as the coil of the electric motor 6 passes through one pole. The three inter-terminal voltages are cyclically shifted by 120 ° from each other due to the arrangement of the pole pairs.

FIG. 4 is a block diagram showing a configuration of the rotation speed calculation means 32 of FIG. The rotation speed calculation unit 32 includes a comparator 33, a counter 34, and a calculation unit 35. The comparator 33 detects a state in which the input inter-terminal voltage reaches zero (zero voltage crossing). The counter 34 counts the number of zero crossings of the voltage and outputs the count value to the calculation unit 35. The calculation unit 35 calculates the rotation speed by the following calculation formula for each calculation cycle.
V = ΔX / (ΔT × a × 6) (1)
However, V is a rotational speed, ΔX is a count increment value, ΔT is a calculation cycle, and a is the number of pole pairs of the electric motor 6.

  Further, the numerical value 6 in the denominator of the equation (1) is configured to count the zero point crossing of the three terminal voltages between the U-V phase, the V-W phase, and the W-U phase. This is in consideration of the zero point crossing from the negative 2 direction.

  In the present embodiment, the case where the speed is estimated based on three inter-terminal voltages is described. However, the speed can be estimated based on three or less inter-terminal voltages. In this case, the numerical value 6 of the denominator of the formula (1) needs to be set to 2 in the case of one set of inter-terminal voltages, and to 4 in the case of two sets. Also, when using two sets of inter-terminal voltages, the phase difference is 120 °, and the two sets of inter-terminal voltages alternately do not reach zero crossing at a constant phase interval, so that an error occurs. There is a need to.

  FIG. 5 is a graph showing how the voltage between terminals varies depending on the rotational speed of the electric motor 6 of FIG. FIG. 5 shows the inter-terminal voltage when the speed gradually decreases with time. When the speed is reduced, the speed at which the coil and the magnet of the motor 6 pass each other is reduced and the induced voltage is reduced, so that the touch width of the voltage is reduced. In addition, since the frequency at which the coil and the magnet pass each other decreases, the frequency of the zero point crossing of the voltage also decreases. For this reason, there are several zero-point crossings during the calculation cycle at a high speed (for example, t1 to t2 in FIG. 5), but none occurs at a low speed ( For example, t3 to t4 in FIG.

  Further, considering the number of pole pairs a of the electric motor 6 of a general elevator apparatus and the calculation cycle ΔT of the apparatus for controlling the electric motor 6 and the like, the speed V directly calculated by the expression (1) is sufficient for use in the control. In many cases, it does not have resolution. On the other hand, if a moving average value for a plurality of calculation cycles is used, a more accurate speed can be detected even at a low speed where the calculation cycle ΔT is small with respect to the time when the count increases by one.

In particular, the number of times of averaging can be determined as follows from the relationship with the speed resolution required for control.
m = 1 / (ΔT × V0 × a × 6) (2)
However, m is the number of times of averaging and V0 is the speed resolution. If the averaging count is m times or more, a velocity resolution of V0 or higher can be obtained.

  In such an elevator apparatus, the brake control device 28 controls the braking force generated by the brake device 8 with reference to the speed estimated by the speed estimator 30 when the car 1 is in an emergency stop. Without newly providing a rotation sensor, the car 1 can be gently stopped without any structural restrictions and at low cost. That is, even in the sensorless control method, the speed of the car 1 can be controlled at the time of emergency stop.

  Further, since the speed estimator 30 estimates the rotational speed of the electric motor 6 based on the induced voltage generated in the electromagnetic coil when the electric motor 6 rotates, the speed is estimated even when the power supply from the inverter 22 to the electric motor 6 is cut off. Can be estimated.

Embodiment 2. FIG.
Next, FIG. 6 is a block diagram showing a speed estimator of an elevator apparatus according to Embodiment 2 of the present invention. The speed estimator 30 includes a rotation direction calculation means 36 in addition to the configuration of FIG. The rotation direction calculation means 36 calculates the rotation direction of the electric motor 6 with the two sets of inter-terminal voltages as inputs, and outputs it as rotation direction information. The configuration of other elevator apparatuses is the same as that in the first embodiment.

  FIG. 7 is a graph showing the change over time in the voltage between the two terminals when the motor 6 in FIG. 1 rotates at a constant speed, and FIG. 8 shows the voltage between the two terminals when the rotation direction is opposite to that in FIG. It is a graph which shows a time change. 7 and FIG. 8 are different in the order of positive / negative switching of the voltage between the U-V phase terminals and the voltage between the V-W phase terminals. That is, in FIG. 7, the V-W phase terminal voltage rotates forward after the U-V phase terminal voltage rotates in the normal direction, whereas in FIG.

  The rotation direction calculating means 36 determines the rotation direction of the electric motor 6 from the order of voltage positive / negative switching shown in FIGS. The rotation direction calculation means 36 may determine the rotation direction based on the input of three sets of inter-terminal voltages. In this case, the detected inter-terminal voltage is increased by one set, so that it is less than in the case of two sets. This can be determined by the phase difference depending on the rotation amount.

  The brake control device 28, when the car 1 is emergency stopped by an emergency stop command from the elevator control device 21 or the like, the rotation amount, the rotation speed of the electric motor 6 grasped based on the speed information estimated by the speed estimator 30, or The on / off control of the control brake switch 26 is controlled so that the rotational acceleration approaches the target value.

  At this time, by providing the rotation direction calculating means 36 in the speed estimator 30, the rotation direction can be determined, so that the reverse rotation after the rotation of the electric motor 6 is temporarily stopped can be prevented more reliably. Further, the target value can be changed according to the rotation direction.

  For example, if there is a margin from the top of the car 1 stopped on the top floor to the ceiling of the hoistway, but there is no margin from the bottom of the car 1 stopped on the bottom floor to the floor of the hoistway By judging whether the car 1 is moving up or down from the rotation direction thus set, the target value is set so that the stopping distance at the emergency stop is shorter when the car 1 is lowered than when the car 1 is raised The car 1 can be slowly decelerated according to the margin distance.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described. In the third embodiment, the forced deceleration device 29 stops the car 1 within a desired distance based on a signal from the governor encoder 13 that is a state sensor that detects the state of the car 1 at the time of emergency stop. The brake device 8 is operated by the forced brake switch 27 as described above. Other configurations are the same as those in the first or second embodiment.

  Even if the car 1 reaches the terminal floor at the time of an emergency stop, safety is ensured by the shock absorbers 9 and 10, but the user cannot get out of the car 1 immediately and the serviceability is lowered. In addition, when the user opens the car door by mischief during traveling, it is desirable to stop the car 1 at a short distance in a range in which the impact caused by the deceleration does not give a burden in consideration of the safety of the user. From such a point of view, it is desirable to adopt a configuration that can satisfy the required specifications more reliably for a stop distance limit request.

  On the other hand, when the speed is estimated by the speed estimator 30, the accuracy and accuracy of the estimated speed are inferior compared to the case where the rotation sensor is used, and the stop distance limit requirement specification can be sufficiently satisfied. It may not be possible.

  Therefore, in the third embodiment, the forced deceleration device 29 is provided with a function of operating the forced brake switch 27 so as to satisfy the stop distance restriction requirement specification, thereby preventing deterioration in serviceability and the door opening event during traveling. Corresponding to

  Here, the brake control device 28 can control the braking force of the brake device 8 based on the signal from the governor encoder 13 without using the speed estimator 30 in the first place. Since the rotation of the electric motor 6 to be braked by the brake device 8 cannot be directly detected, it is difficult to perform control for stopping the car 1 at a reduced speed while sufficiently suppressing vibration of the car 1.

  As shown in FIG. 1, the forced speed reduction device 29 is configured to receive an emergency stop command from the elevator control device 21 in addition to the car position information from the governor encoder 13. To operate.

  FIG. 9 is a graph showing the time change (a) of the car speed and the time change (b) of the state of the forced brake switch when the stop distance is limited by the forced speed reducing device 29 according to the third embodiment. In the figure, a dotted line A is a target speed when the brake control device 28 controls the control brake switch 26, and a thin line B is a forced deceleration device 29 that turns off the forced brake switch 27 to limit the stop distance. Is the target speed.

  If at least one of the control brake switch 26 and the forced brake switch 27 is turned off, the electric motor 6 is decelerated by the brake device 8 due to the configuration of the device. Further, if the brake control device 28 can follow the speed of the electric motor 6 to the target speed based on the estimated speed, the forced brake switch 27 does not operate the brake device 8.

  However, if the brake control device 28 cannot properly follow the target speed and the motor 6 has increased beyond the target speed B, the forced deceleration device 29 turns off the forced brake switch 27 and turns on the brake device 8. To limit the stopping distance. Thus, the target speed B is a pattern that serves as a judgment reference for forced deceleration when the control of the target speed A does not work properly, and is therefore set to a speed higher than the target speed A.

  From the relationship between the functions of these target speeds A and B, if the target speed A is set based on the car speed at the start of emergency stop, the command can be followed without causing a rapid speed change.

  The forced deceleration device 29 determines whether or not the car 1 can actually be stopped within an allowable distance when the brake device 8 is decelerated from the current speed, and the forced brake switch 27 is operated. The distance may be limited by operating.

  FIG. 10 shows the relationship (a) between the car speed and distance (movement distance from the start of emergency stop) when the stopping distance is limited by a method different from the method described in FIG. 9, and the state and distance of the forced brake switch 27. It is a graph which shows the relationship (b).

  In this method, when the relationship between the car speed and the position reaches a speed range equal to or higher than the condition C, the forced brake switch 27 is turned off and the brake device 8 is operated. As a result, when the relationship between the car position and the speed reaches C or more, the brake device 8 always operates. Therefore, when the vehicle travels a predetermined distance according to the pattern of the condition C, the brake device 8 is always operated. Therefore, the distance to stop can be limited by more reliable deceleration.

  As described above, in the elevator apparatus according to the third embodiment, the forced deceleration device 29 causes the forced brake switch 29 to stop the car 1 within a desired distance based on the signal from the governor encoder 13 at the time of emergency stop. 27, the brake device 8 is operated, so that the speed governor encoder 13 detects the position of the car while performing high-precision control by preventing the occurrence of vibration and the like by directly estimating and controlling the rotation of the electric motor 6. The car 1 can be stopped more reliably, and serviceability and safety can be improved.

Note that, as the forced brake switch 27, a forced separation switch that is turned off at the time of failure may be used. In this case, even when the forced brake switch 27 fails, the car 1 can be decelerated more reliably.
Further, the forced brake switch 27 may be duplexed in series. In this case, even if one of the forced brake switches 27 breaks down, the car 1 can be decelerated more reliably by the other forced brake switch 27.
Furthermore, it is good also as a structure which ensures operation | movement of the governor encoder 13 by duplicating the governor encoder 13 and inputting it into the forced deceleration device 29 and comparing two input signals.
Furthermore, it is good also as a structure which ensures the accuracy of judgment by duplicating the judgment part which compares the input of the duplicate governor encoder 13. FIG.

  The elevator control device 21, the brake control device 28, the forced deceleration device 29, and the speed estimator 30 each have a microcomputer. That is, the functions of the elevator control device 21, the brake control device 28, the forced deceleration device 29, and the speed estimator 30 can be realized by using a calculation process by a microcomputer. Also, some of these functions can be executed together by a common microcomputer. For example, the function of the speed estimator 30 and the function of the brake control device 28 may be executed by a common microcomputer. Furthermore, these functions can also be realized by an analog electric circuit that processes analog signals.

  Furthermore, in the above example, the brake device 8 is provided in the hoisting machine 4, but it may be provided in another position. For example, the brake device may be a rope brake that grips the suspension means 3 to brake the car 1, a car brake that is mounted on the car 1 and engages with a guide rail to brake the car 1. However, when the speed is estimated from the induced voltage of the electric motor 6, it is preferable that the brake device is arranged in the electric motor 6 or in the vicinity thereof.

Furthermore, the number of brake devices is not limited to one, and a plurality of brake devices may be used.
1 shows a 1: 1 roping elevator apparatus in which the hoisting machine 4 is arranged in the upper part of the hoistway. However, the layout of the entire elevator apparatus is not limited to FIG. It may be roping or the like.
Furthermore, in the above example, the car 1 is moved up and down by one hoisting machine 4, but an elevator apparatus using a plurality of hoisting machines may be used.
Furthermore, the state sensor is not limited to the governor encoder 13, but may be an optical sensor that detects the position of the car 1, a proximity sensor, a position detection switch, or the like.

  DESCRIPTION OF SYMBOLS 1 Car, 6 Electric motor, 8 Brake apparatus, 13 Speed governor encoder (state sensor), 21 Elevator control apparatus, 28 Brake control apparatus, 29 Forced deceleration apparatus, 30 Speed estimator.

Claims (4)

Basket,
An electric motor for driving the car,
An elevator control device for controlling the electric motor;
A brake device for braking the running of the car;
A brake control device for controlling the brake device, and a speed estimator for estimating the rotational speed of the electric motor,
The said brake control apparatus controls the braking force which the said brake device generate | occur | produces with reference to the speed estimated by the said speed estimator at the time of an emergency stop. The electric motor is a permanent magnet electric motor using a field by a permanent magnet,
The elevator apparatus according to claim 1, wherein the speed estimator estimates a rotation speed of the electric motor based on an induced voltage generated in an electromagnetic coil when the electric motor rotates. The speed estimator estimates the rotation direction of the electric motor from the order of positive / negative switching of the voltage between the terminals of the electric motor,
The elevator device according to claim 2, wherein the brake control device controls a braking force generated by the brake device with reference to a speed and a rotation direction estimated by the speed estimator at an emergency stop. . A state sensor that detects the state of the car, and a forced reduction device that operates the brake device based on a signal from the state sensor,
The elevator according to any one of claims 1 to 3, wherein the forced deceleration device operates the brake device so as to stop the car within a desired distance during an emergency stop. apparatus.

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